Winter vegetable garden tasks

Use shovel to turn soil
Freezing soil

Winter starts around the third week of December in the northern hemisphere, which includes the United States. USDA plant hardiness zones from zones 1 through 6 experience frozen soil during the winter. The depth of the frozen soil varies from 6 inches in the affected southern USDA zones and as much as 72 inches in the northern zones. The National Snow and Ice Data Center (NSIDA) provides a chart of the U.S. depicting seasonally frozen ground. The NSIDA says that we can expect different rates of ground freeze because sandy soil freezes easier than clay soil. It may take several repeated days of below freezing air temperature to cause the water in the soil to freeze. Before and after the ground freezes, complete these vegetable garden tasks. 

Use shovel tip to break clumps
Garden tasks before the ground freezes

Dig weeds or grass from the garden. Add about 6 inches of leaf mold, which is decaying leaves that form organic fertilizer. Rake fall leaves evenly over the garden. Use a rototiller or shovel to work the leaves down to a depth of 4 to 6 inches. If using a shovel, force the shovel into the soil as far as you can and then turn over the shovel load of soil and leaves. Water the soil to promote leaf decay.

Garden tasks after the ground freezes
 
Examine and repair fences and trellis structures for climbing plants. Sharpen and lubricate garden tools. Pull or spray weeds along garden pathways. If you use mechanical garden tools, like a rototiller or garden tractor, winter is a good time to have them undergo routine service.

When it is too cold outdoors to work, take a seat in your favorite chair indoor for another winter gardening task. Peruse seeds catalogs or garden supply stores online to order seeds. Seed shopping in the winter reduces the chance that the distributor might run out of the seeds if you wait until spring to start shopping. 

Consider buying hybrid seeds for your vegetable garden. Hybrid seeds are a good choice for collecting and drying seeds from the current planting season to use the following season. In a University of Minnesota Extension article, Saving Vegetable Seeds, the recommendation for easy seed collection is from tomatoes, peppers, beans, and peas. Store the dried seeds in envelopes kept inside a sealed plastic bag and placed in the refrigerator. You may never need to buy seeds again.